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Abstract:

A trim part has an airbag cover that opens in a hinged fashion. The trim
part includes a retaining element that is connected on a first end to the
airbag cover and on a second end to an anchor such that the retaining
element has an excess length. At least one of the two ends is connected
to a strip that includes webs that extend from the strip and that take up
at least part of the excess length.

Claims:

1-12. (canceled)

13. A trim part comprising: a hinged airbag cover; a flexible flat
retaining element having a first end and a second end, the first end of
the flexible flat retaining element secured to the airbag cover, the
flexible flat retaining element having an excess length; an anchor, the
second end of the flexible flat retaining element secured to the anchor;
at least one strip that is oriented transversely relative to a loading
direction of the retaining element, at least one of the first and second
ends of the flexible flat retaining element being connected to the at
least one strip, the at least one strip being secured on the airbag cover
or on the anchor; and webs molded on the at least one strip, the webs
oriented transversely to the at least one strip and being connected to
the flexible flat retaining element, the webs taking up at least a part
of the excess length.

14. The trim part of claim 13, wherein the at least one strip and the
webs are integrally molded with the flexible flat retaining element being
embedded in the strip.

15. The trim part of claim 14, wherein the webs are integrally molded
with the flexible flat retaining element.

16. The trim part of claim 14, wherein parts of the flexible flat
retaining element are integrally molded around the webs.

17. The trim part of claim 13, wherein the webs begin at an edge of the
strip at which the flexible flat retaining element leaves the strip.

18. The trim part of claim 13, wherein the webs follow a curved course
away from the flexible flat retaining element between the first and
second ends of the flexible flat retaining element.

19. The trim part of claim 13, wherein the webs have a length that is
between about 5 millimeters and about 30 millimeters.

20. The trim part of claim 13, comprising a total of about 2 to about 12
webs.

21. The trim part of claim 13, wherein the flexible flat retaining
element comprises a band or mat made of a textile material.

22. The trim part of claim 13, wherein the at least one strip is welded,
screwed or riveted to either the airbag cover or the anchor.

23. A method for producing a trim part having a hinged airbag cover by
connecting a trim part blank and a flexible flat retaining element, the
trim part blank including a hinged airbag cover for covering a passage
opening for an airbag, the flexible flat retaining element having two
ends, at least one of the two ends being connected to a strip, the
flexible flat retaining element having an excess length, the method
comprising: securing a first of the two ends of the flexible flat
retaining element on the airbag cover; and securing a second of the two
ends of the flexible flat retaining element on an anchor such that the
strip is secured on the airbag cover or on the anchor, an excess length
of the retaining element remaining between the airbag cover and the
anchor; wherein when securing the strip on the airbag cover or on the
anchor, jamming of the retaining element is prevented by webs that are
molded on the strip and that are orientated transversely relative to the
strip, the webs being connected to the retaining element and taking up at
least a part of the excess length of the retaining element.

24. The method of claim 23, wherein the strip is injection molded such
that the flexible flat retaining element is embedded in the strip.

25. The method of claim 23, wherein the webs are configured in one piece
with the strip and are injection molded onto the flexible flat retaining
element.

26. The method of claim 23, wherein the strip is welded, screwed or
riveted to either the airbag cover or the anchor.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a national phase application of PCT
application PCT/EP2008/009831 filed pursuant to 35 U.S.C. §371,
which claims priority to DE 10 2007 055 016.4, filed Nov. 14, 2007. Both
applications are incorporated herein by reference in their entirety.

TECHNICAL FIELD

[0002] The invention relates to a trim part having a hinged airbag cover
that is linked via a flexible flat retaining element, and also to a
method for producing such a trim part.

BACKGROUND

[0003] A generic trim part may include a retaining element that is secured
by a first end on the airbag cover and by a second end on an anchor that
is spaced apart from the airbag cover and that has an excess length
between the airbag cover and the mentioned anchor, at least one of the
two ends being connected to a strip which is orientated transversely
relative to a loading direction of the retaining element and is secured
on the airbag cover or on the anchor. Such a trim part is known for
example from the publication DE 196 33 109 A1.

[0004] The strip is intended to provide a stable connection of the airbag
cover to the anchor, which connection has sufficient loading capacity to
withstand an opening thrust. The excess length of the retaining element
is typically produced in that the retaining element in the form of a loop
is guided by the anchor to the airbag cover. This is intended to allow
the airbag cover, when the airbag is deployed, to be raised from a
passage opening of the trim part before the retaining element tightens
and then acts as hinge and forces a rotational movement of the opening
airbag cover which is only then possible without being impeded. In the
production of such trim parts according to the state of the art, the
problem arises that the retaining element can jam or become damaged
between the strip and the airbag cover or the anchor because of the
required excess length when securing the strip connected to the retaining
element on the airbag cover or on the anchor spaced apart from the airbag
cover so that only a reduced excess length remains unintentionally and
possibly without being noticed and subsequently, when an airbag is
deployed, an opening movement of the airbag cover is impeded because of
the excess length being too small.

SUMMARY

[0005] The invention pertains to a corresponding trim part in which
jamming or damage to the retaining element during production of the trim
part is reliably prevented without causing the production of the trim
part to become more complex. Furthermore, the invention pertains to a
method which is improved in this respect for producing such a trim part.

[0006] An embodiment of the invention pertains to a trim part having a
hinged airbag cover. A flexible flat retaining element has a first end
secured on the airbag cover and a second end secured on an anchor spaced
apart from the airbag cover. The flexible flat retaining element has an
excess length between the airbag cover and the anchor. At least one of
the two ends is connected to a strip that is oriented transversely
relative to a loading direction of the retaining element and is secured
on either the airbag cover or the anchor. The strip includes webs that
are molded on the strip. The webs are oriented transversely relative to
the strip and are attached to the retaining element at least at places.
The webs take up at least a part of the excess length of the retaining
element.

[0007] Another embodiment of the invention pertains to a method for
producing a trim part having a hinged airbag cover. A trim part blank is
provided, the trim part blank including an airbag cover that covers a
passage opening for an airbag. A flexible flat retaining element having
at least one of two ends connected to a strip is provided. The retaining
element is connected to the trim part blank by securing a first of the
two ends on the airbag cover and by securing a second of the two ends on
an anchor spaced apart from the airbag cover. The strip is secured on the
airbag cover or on the anchor such that an excess length of the retaining
element remains between the airbag cover and the anchor. When securing
the strip on the airbag cover or on the anchor, jamming is prevented by
webs that are molded on the strip and that are oriented transversely to
the strip. The webs are connected at least at places to the retaining
element and take up at least a part of the excess length of the retaining
element.

[0008] The webs that are orientated transversely relative to the strip,
are connected to the retaining element at least in places and take up at
least a part of the excess length of the retaining element, reliably
prevent jamming of the retaining element behind the strip when securing
the strip on the airbag cover or on the anchor. Damage to the retaining
element can thus be avoided because the retaining element, when
connecting the retaining element, which is connected to the at least one
strip, to the airbag cover and to the anchor, is forced by the webs into
a defined position in which the retaining element is not or only slightly
slack. The webs are thereby expediently configured to be so weak that
they do not impede extension of the retaining element during an opening
movement of the airbag cover.

[0009] A correspondingly advantageous method for producing a trim part of
the type proposed here correspondingly provides that a flexible flat
retaining element for the airbag cover, which is connected by at least
one of two ends to a strip, is connected to a blank of the trim part with
a hinged airbag cover, by securing a first of the two ends on the airbag
cover and a second of the two ends on an anchor spaced apart from the
airbag cover in that the at least one strip is secured on the airbag
cover or on the anchor, an excess length of the retaining element
remaining between the airbag cover and the mentioned anchor and jamming
of the retaining element being prevented by webs which are molded on the
strip and orientated transversely to this strip, which webs are connected
to the retaining element at least at places and take up at least a part
of the excess length of the retaining element.

[0010] The strip can thereby be produced in an advantageously simple
manner by injection molding, a connection of the strip to the retaining
element then being able to be produced in that the retaining element is
injected around during production of the strip and thus is embedded in
the strip. In some embodiments, the strip is produced from a
thermoplastic plastic material. The webs can be configured in a likewise
simple manner in one piece with the strip and injection molded onto the
retaining element, for example in such a manner that a material forming
the webs surrounds at least some fibers of a material which forms the
retaining element and is typically a textile.

[0011] In some embodiments, the webs are disposed such that they begin at
one edge of the strip at which the retaining element leaves the strip. In
order to take up at least a part of the excess length of the retaining
element such that the latter is retained in a defined shape by the webs,
the webs can follow a curved course, as opposed to a direct connecting
line, between the two ends of the retaining element away from the airbag
cover.

[0012] In some embodiments, the excess length of the retaining element is
dimensioned such that the retaining element is tightened during opening
of the airbag cover only when the airbag cover has covered a path
corresponding approximately or at least to one thickness of the trim part
in order that an opening movement is then possible without being impeded.
In some embodiments, the webs have a length of approximately the same
order of magnitude in order to be able to take up the excess length so
far that jamming or damage to the retaining element during assembly is
prevented. In some embodiments, the length of the webs is between about 5
mm and 30 mm for this purpose. The webs should thereby not be too thick
in order not too greatly to impede extension of the retaining element. In
some embodiments, the webs have a diameter of no more than about 5 mm. In
some embodiments, the webs have a diameter of no more than about 3 mm.

[0013] In some embodiments, in order that the excess length of the
retaining element, with not too complex a design of the corresponding
strip, can be taken up over the entire width of the retaining element,
there may be between two and twelve webs connected at least in places to
the retaining element. In some embodiments, there may be at least three
or four webs connected to the retaining element at least at places.

[0014] During production of the trim part, the at least one strip
connected to the retaining element can be connected, in a particularly
simple manner, by welding, screwing or riveting to the airbag cover or
the anchor such that a connection which has sufficient loading capacity
and also withstands deployment of the airbag is produced.

[0015] Typically, the retaining element is connected at both ends
respectively to a strip orientated transversely relative to the loading
direction, i.e. parallel to a corresponding edge of the airbag cover, one
of these strips being secured on the airbag cover and the other on the
anchor spaced apart from the airbag cover. The anchor can thereby
concern, for example, a part of a support of the trim part, a wall or
another part of a deployment channel for the airbag or another support
part behind the trim part. If the retaining element is secured with two
stripsassembly of the retaining element can be effected in a particularly
advantageous manner after the actual production of the trim part or of a
blank of the trim part. Hence the production of the blank is simplified
because for example complex introduction of the retaining element into a
molding tool for the trim part or into a support of the trim part is
unnecessary. In some embodiments, the webs may be molded moulded on the
strip which is secured on the airbag cover. In some embodiments, the webs
may be molded on the other strip secured on the anchor spaced apart from
the airbag cover. If the airbag hinge is intended to be configured in a
non-complex manner as far as possible as a moveable part, molding of the
webs on the strip secured spaced apart from the airbag cover can be
possible. Furthermore, the two strips can be secured in different ways,
for example one strip by welding and the other by a screw connection or
riveting. In some embodiments, the securement method may be chosen as a
function of the material of the airbag cover or of the anchor and as a
function of geometric conditions.

BRIEF DESCRIPTION OF THE FIGURES

[0016] An embodiment of the invention is explained subsequently with
reference to FIGS. 1 to 3.

[0017] FIG. 1 is a cross-section through a trim part in one embodiment of
the invention,

[0018] FIG. 2 is an enlarged section of the cross-section of FIG. 1 and

[0019] FIG. 3 is a perspective view of components of the trim part of
FIGS. 1 and 2.

DETAILED DESCRIPTION

[0020] A trim part can be detected in FIG. 1, which concerns a part of an
instrument panel behind which a passenger airbag (not illustrated in FIG.
1) is disposed. The trim part has a support 1 made of a thermoplastic
plastic material, a foamed intermediate layer 2 and a decorative surface
3. The trim part includes a hinged airbag cover 4 which is disposed above
or in front of the mentioned passenger airbag.

[0021] The airbag cover 4 has its own support part 5 which fills a passage
opening in the support 1. In addition, the intermediate layer 2 and the
decorative surface 3 are weakened along an edge of the airbag cover 4 so
that the airbag cover 4, when the airbag is deployed, can be released by
the opening impact acting then on the support part 5 and thus can release
the passage opening.

[0022] To prevent the airbag cover 4 from escaping unimpeded into a
vehicle interior, the airbag cover 4 is joined via a flexible flat
retaining element 6 that is a net-shaped mat manufactured from a textile
material, said mat being approximately as wide as the support part 5. For
this purpose, the retaining element 6 is secured by a first end on the
airbag cover 4 and there on the support part 5 and by a second end on a
part of a deployment channel 7 serving as anchor. In some embodiments,
instead of a mat, a plurality of bands, disposed in parallel, could serve
as the retaining element 6. Between the airbag cover 4 and the anchor on
the deployment channel 7, the retaining element 6 has an excess length
which allows the airbag cover 4, when an airbag is deployed, to move
firstly out of the passage opening so far that an unimpeded hinging
movement becomes possible before the retaining element 6 tightens and
forces the airbag flap 4 into this hinging movement. The retaining
element 6 then acts as airbag flap hinge. In FIG. 1 arrows marked above
the airbag 4 illustrate a movement which is performed consequently by the
airbag cover 4 when an airbag is deployed.

[0023] In some embodiments, in order to secure the retaining element 6,
the two ends of the retaining element 6 are connected to two strips 8 and
9 which are orientated transversely relative to a loading direction of
the retaining element 6, i.e. perpendicular to a drawing plane of FIG. 1,
the strip 8 connected to the first end being secured on the support part
5 of the airbag cover 4 and the strip 9 connected to the second end being
secured on the anchor provided by the deployment channel 7.

[0024] On the strip 9, webs 10 which are orientated transversely relative
to this strip 9 are molded. The webs 10 are connected to the retaining
element 6 and take up the excess length of the retaining element 6 such
that the retaining element 6 has almost no more slack and is retained by
the webs 10 in a defined shape and position.

[0025] A partial region encircled in FIG. 1 by a broken line is
represented once again in more detail in FIG. 2. The same features are
thereby provided again with the same reference numbers. The strips 8 and
9 are injection molded parts which are manufactured from thermoplastic
plastic material and in which the respective end of the retaining element
6 is embedded. For this purpose, the retaining element 6 is introduced
into a corresponding casting mold so that the two ends of the retaining
element 6 were injection molded around during production of the strips 8
and 9. The webs 10, eight of which, in the present embodiment, are
disposed distributed over a width of the airbag cover 4 or along the
strip 9, are configured in one piece with the strip 9 and, during
production of the strip 9, were injection molded in the same molding tool
on the retaining element 6 such that at least some fibers of the
retaining element 6 are surrounded by a material forming the webs 10. For
this purpose, the webs 10 begin at an edge of the strip 9 orientated
towards the strip 8, at which the retaining element 6 leaves the strip 9.
In order to take up the excess length of the retaining element 6, the
webs 10, of which only a first respectively can be detected in FIGS. 1
and 2, follow a curved course, as opposed to a direct connection line,
between the two strips 8 and 9 away from the airbag cover 4. The webs 10
thereby have a diameter of about 2.5 mm and a length of about 15 mm.

[0026] The strip 9 is connected by screws 11, indicated in FIG. 2, to the
part of the deployment channel 7 serving as anchor. Instead of the screws
11, for example rivets could also be used for securing the strip 9. The
other strip 8 is welded onto the support part 5 which is likewise
manufactured from a thermoplastic plastic material. It can be welded in
particular for example by ultrasonic welding or can have been welded by
energy direction sensor welding. This allows subsequent securing of the
retaining element 6 after production of a blank of the trim part provided
by the remaining components of the trim part. This facilitates production
of this blank, for which for example the decorative surface 3 is
back-foamed and thus can be connected to the support 1 and to the support
part 5. If the retaining element 6 which is firstly embedded by its ends
in the strips 8 and 9 and connected to the webs 10 is connected to the
thus produced blank of the trim part in that the strip 8 is welded to the
support part 5 and the strip 9 is screwed to the deployment channel 7 or
riveted there, jamming of the retaining element 6, provided with the
excess length, between the strip 9 and the deployment channel 7 or
between the strip 8 and the support part 5 is prevented in that the
excess length is taken up at least for the most part by the webs 10 which
retain the retaining element 6 consequently in a defined position. The
webs 10 are designed thereby to be weak enough that they do not impede
extension of the retaining element 6 when the airbag is deployed. In
order to secure the strips 8 and 9, the retaining element 6 formed by a
net-shaped textile is placed with the strips 8 and 9 in a welding tool,
the retaining element 6 being forced by the webs 10 into the shape of a
loop and thus being prevented not only from jamming but also being
protected from damage without the retaining element 6 requiring, in a
complex manner, to be placed in its position before welding and screwing
manually or by robot control. Rather, it suffices to bring the strips 8
and 9 into the desired positions before securing on the support part 5
and on the deployment channel 7.

[0027] In FIG. 3, the strip 9 having the webs 10 and a part of the
retaining element 6 is shown once again in a perspective view. All eight
webs 10 can be detected here. Three borings 12 for receiving the screws
11 which serve to secure the strip 9 can likewise be detected in FIG. 3.
Of course, the webs 10 could also be molded on the other strip 8 instead
of the strip 9, which strip 8 is secured on the airbag cover 4. The strip
9, which is secured here on the deployment channel 7 designed in one
piece with the support 1, could in turn alternatively also be secured on
other supporting parts spaced apart from the trim part.

[0028] Finally, it may be explained that the term "strip" used herein
should be understood in a wide sense. It is used here because the
elements described therewith, which are characterized in the embodiments
in the Figures with the reference numbers 8 and 9, are in fact
strip-shaped in typical embodiments of the invention. However, the term
should also include here anchor elements of a different shape which
fulfil the same function.